Partial mash ratio grain and dme/lme

[tschafer]

I've been doing partial mashing since last November, and I love it! And I've generally hit my target OG.

But my last 2 brew have been less than desirable. I'm getting 52-65% efficiency. Not to happy with that.

I've got a good feeling I'm using to much base malt an not enough dme/lme in my recipes.

What is a good ratio for with grain and DME/LME? 60/40?

 

[lumpher]

there is no ratio for this. you use what you want. i think your problem may be you're steeping the grain, not mashing it. are you soaking it at 150 or so for an hour, or are you soaking it at 160 for 20 minutes?

 

[ChshreCat]

I use beersmith to calculate that on a recipe by recipe basis. It works really well in that I can load an all grain recipe, back the grain off until it's down to an amount I can do and then add LME until the numbers come back up to where the original recipe was. Try a free trial of it. Makes it way easy.

 

[tschafer]

Lumpher- no, I'm mashing @ 154-156 for 60 and sparging for 15 minutes @ 170. No steeping here.

CC- I need to take a look at beer smith again.

It's just abit frustrating that my last 2 brews have had a low efficiency.

 

[ChshreCat]

What are you using to mash/sparge in?

 

[chickypad]

Did something change with your process on the last 2 brews? Like crush, sparge, thermometer calibration, recipe issues (i.e enough base grains for diastatic power).

 

[EyePeeA]

OP, read this link: http://beersmith.com/blog/2010/01/04/diastatic-power-and-mashing-your-beer/

"Diastatic power plays an even more important role for partial mash brewers. Many beginning partial mash brewers tend to take several pounds of specialty malts and try to mash them without a pale base malt. This can cause very poor conversion, as the fermentable portion of the specialty malts lack the enzymes to convert. It is important that you mash with sufficient base malt to provide the enzymes needed in the mashing process."

 

[454k30]

EyePeeA has it right. This was one I learned by mistake as well. My aha moment came while doing a PM doppelbock and my OG was much higher than expected. In that grainbag was some base malt that got everything else going. Before that I just used grains for color and flavor and had to boost my LME addition to make up for low efficiency. I go through mashing steps now instead of just steeping.

 

[tschafer]

CC - MASH is in a 6.5 GAL pot, Paint strainer bag. 1 - 1.25 quart water for every pound of grain, pull grains after 60, raise temp, place grain (still in bag) on a double mesh strainer over the pot. Sparging with a measuring cup.

Chickpad - two different recipes, Honey Brown Ale, and a IPA. Honey Brown got 63% efficiency, and the IPA got a whooping 52%.

11% DME was used in the HoneyBrown's Grain Bill

IPA used 26% LME. The rest was base malts in both recipes...

In both recipes, my extract have been low and I feel that's got to be why I'm getting such a low efficiency.

So if there was a base ratio of grain and extract for partial I would have like to know.

I do feel like I need to decease the grain abit and increase the DME/LME to get back to 75-85% efficiency.

 

[ChshreCat]

Now, when you refer to your efficiency... are you taking a gravity reading before you boil? Or are you calculating from your reading you do after the boil to get your OG?

Also, are these partial boil recipes with top up water or are they full boil?

 

[pagerage]

I am looking for an answer to this question, sort of too. But my question isn't in the ratio of base malts to DME, it is the ratio of base malts to specialty grains. I have read that for a proper conversion you need to have the appropriate amount of base malts in ratio to specialty grains. I have read everything from a 1 to 1 ratio as well as people say simply put 2 pounds of base malts in there.

I think some specialty grains like Victory, Munich, or roasted barley have enough diastatic power to convert on their own like a base malt. But then grains like flaked barley or Crystal need the base malt to covert to fermentable sugar.

Can anyone give some info on this or point to a reliable source? I can see this as a possibility for not hitting the specific OG for a recipe.

 

[Yooper]

I am looking for an answer to this question, sort of too. But my question isn't in the ratio of base malts to DME, it is the ratio of base malts to specialty grains. I have read that for a proper conversion you need to have the appropriate amount of base malts in ratio to specialty grains. I have read everything from a 1 to 1 ratio as well as people say simply put 2 pounds of base malts in there.

I think some specialty grains like Victory, Munich, or roasted barley have enough diastatic power to convert on their own like a base malt. But then grains like flaked barley or Crystal need the base malt to covert to fermentable sugar.

Can anyone give some info on this or point to a reliable source? I can see this as a possibility for not hitting the specific OG for a recipe.

Well, you can look up the diastastic power for each grain, if you want to be specific. But in general, you can be safe in assuming that 1 pound of base malt will work to convert itself + 1 pound of specialty grains.

Some grains do convert themselves (Munich, for example), but those are also base malts and not grains like Victory or roasted barley.

If you're using a lot of adjuncts (flaked corn, oats, etc), then I"d consider raising the amount of base malt but overall a 1-for-1 guestimate is just fine.

 

[pagerage]

Corrected

 

[pagerage]

Thanks for info Yooper! And coming from someone like you (expert) I feel pretty confident in the response.

So basically look at the specialty portion of the grain bill and match it 1 to 1 for the total (minus any other malts that can convert themselves)

Sounds like a guesstimate that will work for me!

 

[tschafer]

Cc- after the boil, and chilled and topped off with water.

 

[chickypad]

Efficiency doesn't really apply to extract - a known amount will increase the gravity a known amount in a given volume. You may be dealing with mixing issues if you topped off and then took a gravity.
If you want to check the efficiency of your partial mash you need to check the gravity of that wort before adding extract and before topping off. If you know the volume you can then calculate your efficiency.

 

[ChshreCat]

Cc- after the boil, and chilled and topped off with water.

Then I'm guessing that you're not getting an accurate reading. When you top up a concentrated wort, it's really easy to end up with stratification with heavier wort sinking to the bottom and lighter, more watery stuff closer to the surface. Depending on where you get your sample from you can end up with a high or low reading.

I usually have my brew assistant (child labor) stir the living crap out of it for a food minute after I top up, then I take my sample while she's still stirring to make sure I get a good sample.

If you really want to see what your mash efficiency is you can take a sample before you start your boil. Just quick cool it down while you're getting the boil started and then add it back to the kettle when your done.

 

[ajf]

Can you post the recipe for one of the two batches where you think you got low efficiency preferably, the batch where you estimated 52% efficiency?

With a partial mash, the extract portion should yield 100% efficiency, while the grain portion will give a lower efficiency, but if you handle the grains correctly you should get >= 65% efficiency from the grains. This means that your overall efficiency will increase with a higher percentage of extracts, or decrease with a higher percentage of grains, but even if you used 99.9999% grains and 0.0001% extract your efficiency should not drop below about 65%. I suspect that you have some faulty OG readings caused by topping off with water and not mixing enough to eliminate stratification.

-a.